build(deps-dev): bump eslint from 6.3.0 to 6.4.0

Bumps [eslint](https://github.com/eslint/eslint) from 6.3.0 to 6.4.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](eslint/eslint@v6.3.0...v6.4.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

yarn.lock

@@ -295,8 +295,8 @@ eslint-visitor-keys@^1.0.0, eslint-visitor-keys@^1.1.0:
   resolved "https://registry.yarnpkg.com/eslint-visitor-keys/-/eslint-visitor-keys-1.1.0.tgz#e2a82cea84ff246ad6fb57f9bde5b46621459ec2"
 
 eslint@^6.0.0:
-  version "6.3.0"
-  resolved "https://registry.yarnpkg.com/eslint/-/eslint-6.3.0.tgz#1f1a902f67bfd4c354e7288b81e40654d927eb6a"
+  version "6.4.0"
+  resolved "https://registry.yarnpkg.com/eslint/-/eslint-6.4.0.tgz#5aa9227c3fbe921982b2eda94ba0d7fae858611a"
   dependencies:
     "@babel/code-frame" "^7.0.0"
     ajv "^6.10.0"